"In the beginning, there is darkness – the emptiness of a matrix waiting for the light. Then a single photon flares into existence. Then another. Soon, thousands more. Optronic pathways connect, subroutines emerge from the chaos and a holographic consciousness is born."

Although his program was originally designed to function in emergency situations only, Voyager's sudden relocation to the Delta Quadrant, combined with the lack of an organic-being physician, necessitated that The Doctor's program be run on a full-time basis, effectively becoming Voyager's chief medical officer. Over the years The Doctor expanded his program a great deal; he acquired many interests and hobbies, developed close personal friendships with many crew members, and even fell in love. He developed into a brilliant yet compassionate man who proved his worth and loyalty to all crew members throughout the years, earning their respect of him as an individual with the same civil and social rights as everyone else on board. (VOY: "Caretaker", "Eye of the Needle", "Lifesigns", "Flesh and Blood", "Author, Author")

The EMH Mark I, upon which The Doctor's program was based, was listed as "Emergency Medical Holographic Program AK-1 Diagnostic and Surgical Subroutine Omega 323" in Voyager's memory. It was developed by a team of engineers to be an emergency supplement to the medical team on starships. Only meant to run for a maximum of 1,500 hours, the program included little personality and interpersonal skills. However, it was capable of treating any known injury or disease, as it was programmed with the medical knowledge of every member world in the Federation and that of over five million surgical procedures. His program even became capable of learning and adapting, in order to create new medical treatments. (VOY: "Projections", "The Swarm", "Caretaker", "Parallax", "Cathexis")

Dr. Zimmerman claimed not to have programmed the EMH Mark 1 with sarcasm--but early episodes of Voyager indicate otherwise. (VOY: "Life Line") This "sarcasm subroutine" could have been a part of the "deficiencies" which Dr. Zimmerman attributed to the Mark 1 program.

The Doctor was first, albeit very briefly, activated as a demonstration by Vice Admiral Patterson for Cpt. Janeway shortly before Voyager's launch on stardate 48038.5 in early 2371. (VOY: "Relativity")

On stardate 48308.2, The Doctor was activated by EnsignHarry Kim to help treat crew members injured in the ship's violent transit to the Delta Quadrant, during which the assigned medical staff had been killed. The Doctor quickly established that the Voyager crew would be stuck with him for a while and that he would be the sole provider of medical care aboard the ship. (VOY: "Caretaker")

"Whatever it is, you're going to have to take care of it yourself."

The Doctor's first few weeks as a full-time medic on Voyager were not easy for him. He had no control over his activation subroutines, so anyone could activate or deactivate his program solely at their choice. Most of the crew considered him merely a computer program or a tool, and treated him accordingly. He, in turn, was curt and rude to them, lacking empathy and bedside manner, and he was unhappy that he was being used to perform menial medical tasks. He felt that his perfection and comparative medical genius were not appreciated. When developing or performing exceptional medical procedures, he often cynically remarked that anywhere else performing such kind of a procedure would have won him a prestigious award. He was also upset at being the last one to be made aware of events that were not directly within his purview, such as the Maquis crew joining Voyager and both Neelix and Kes joining the crew. (VOY: "Time and Again", "Parallax", "Shattered", "Someone to Watch Over Me")

One of The Doctor's first major clinical achievements on board Voyager was creating a holographic lung for Neelix. Neelix had lost his lungs to Vidiians during an organ-harvesting raid. The Doctor devised a plan to use holographic lungs to keep Neelix alive. The Doctor's idea succeeded; however, Neelix was confined to an isotropic restraint and not allowed to move, as the holographic lungs could not move. The Doctor was later able to transplant one of Kes's lungs into Neelix, with help from the Vidiians. (VOY: "Phage")

It was not until Kes volunteered to work with The Doctor as an assistant--and later medical student--that relations between The Doctor and most of the other crew members began to improve. It was Kes who first discovered the crew's disrespectful behavior toward The Doctor; she noticed that, just as with an item of equipment, they never addressed him directly, they barely listened to him, and often exited his presence without deactivating his program. Kes brought the matter to CaptainJaneway's attention, asking that The Doctor be treated with greater respect and granted some interpersonal autonomy. Janeway took Kes's advice to heart--somewhat reluctantly, as she herself was aware of The Doctor's questionable bedside manner--but nonetheless granted him partial control over his activation and program. He was subsequently left hurt when it was revealed that the crew were exploring a means of transporting back to the Alpha Quadrant through a small wormhole, as he was the last one to know about this development and would be left on the ship as it was impossible to download his program at this time (although the matter became academic when it was revealed that the wormhole extended into the past) (VOY: "Eye of the Needle").

The Doctor was sent on his first away mission by Janeway, tasked with rescuing Kim, Tuvok, and Chakotay from a Beowulf holoprogram that had been invaded by a mysterious alien. Janeway's reason for deploying The Doctor on this mission was that, as a hologram, he was the only one who could not be snatched from the holodeck. The Doctor did, however, lose an arm on his first encounter with the being, which had manifested itself as the monster Grendel. Samples of photonic energy had been accidentally beamed aboard Voyager and this energy was part of the alien inhabiting the holodeck. Once returned to the alien, the crew was released. (VOY: "Heroes and Demons")

When the mental energy of Chakotay and the Komar was possessing members of Voyager's crew, The Doctor was the only crew member who could not be controlled. As no one but he could be trusted, given that the Komar could inhabit anyone at any time, Janeway transferred her command codes to The Doctor so that he could countermand orders he believed were initiated due to the alien's influence. However, his program's initialization routine was later deactivated until the incident with the Komar ended. Once reactivated, the Doctor was able to reintegrate Chakotay's displaced neural energy with his body, in a procedure that required three neural transceivers, two cortical stimulators, and fifty gigaquads of computer memory, and would take about ten hours to explain to others. (VOY: "Cathexis")

An accident aboard Voyager once caused The Doctor to confuse illusion with reality. A hallucination of LieutenantReginald Barclay told The Doctor that he was real, that he was actually Lewis Zimmerman and married to a very human Kes. The illusory Barclay persuaded The Doctor that he was held within a hologram of Voyager, with radiation after an accident having killed him. The Doctor became convinced that the only way to escape was to fire a phaser into Voyager's warp core, an act that seemingly would result in the simulation's destruction. At the last possible second, Chakotay convinced The Doctor that he was about to destroy his own matrix. The problem was solved, although The Doctor was left intrigued as to why he had hallucinated about the nature of his existence rather than simply having had his program's defenses activated. (VOY: "Projections")

The same year, The Doctor diagnosed that Kes's sexual maturation, the elogium, had been prematurely activated by a swarm of space-dwelling aliens. During this period he acted in the role of Kes's father by performing the necessary rituals with her, such as the rolissisin, a ritual in which the feet are massaged until the tongue swells. Kes's elogium ended when Voyager cleared the aliens' territory. The Doctor hypothesized that the elogium had been prematurely triggered by the aliens and that Kes would still be able to conceive at her natural age of elogium. (VOY: "Elogium")

In 2372, The Doctor still didn't consider himself a true member of the Voyager crew. He felt he was not being kept sufficiently informed about ship business and missions. As a result, he was forced to repeatedly open communications channels all over the ship in order to find out what was going on, an activity Captain Janeway asked him to discontinue. (VOY: "Parturition")

In response to criticism that he was unsympathetic to his patients, he programmed himself with the Levodian flu for twenty-nine hours to simulate the effects and to prove that a little illness should not be grounds for a constantly whiny and cranky attitude, which he accused the Voyager crew of every time they entered sickbay. Thirty hours later the simulated flu still had not cleared him, and The Doctor became fearful, feeling helpless and not in control. Kes later admitted that she had extended the simulation unbeknownst to him to teach him a real-life lesson, as it would hardly have been a real illness if he had known the outcome. (VOY: "Tattoo")

Danara Pel's holographic body

Despite initial irritations and frictions, The Doctor also experienced new things in the personal growth and romance department. When a Vidiian scientist named Danara Pel was beamed aboard Voyager to be treated, The Doctor transmitted her synaptic pathways into a hologram of her body without the disease and put her real body in stasis until he could find a cure for her breakdown. He grafted a piece of B'Elanna Torres' brain tissue onto Pel's brain, as KlingonDNA had been found to be resistant to the phage. Over time he became attracted to her, but as he was inexperienced in the matters of the heart, he did not know how to handle his new-found emotions and confess his feelings to Denara. After receiving some advice from crew members such as Kes and Tom Paris, he overcame his initial awkwardness and took Denara on a date on the holodeck. When a cure for her condition was found and The Doctor was finally able to take Denara out of stasis, she refused, stating that she did not want to go back to that deformed body. The Doctor assured her that he loved her no matter what she looked like and that he would not want her to give up her life. The Doctor and Denara spent two weeks with one another before she met with her people and had to leave Voyager. (VOY: "Resolutions")

Voyager entered a plasma cloud which caused the ship and its crew to be duplicated. The Doctor was on one of the ships and delivered Ensign Samantha Wildman's baby, who died shortly after birth. After the other ship was invaded by Vidiians, The Doctor on that ship saved that Ensign Wildman's baby, keeping it hidden from the Vidiians until that Kim and the baby could board the "first" Voyager, which they did just before their ship self-destructed, killing the Vidiians and saving the "first" Voyager. (VOY: "Deadlock")

When a transporter accident combined Tuvok and Neelix into a single entity named Tuvix, The Doctor found a way to separate and restore them. However, he refused to perform the procedure as he would have to kill Tuvix, a sentient being in his own right who had refused to consent to the separation. Captain Janeway eventually performed the procedure in his stead. (VOY: "Tuvix")

When Voyager discovered a group of alien survivors trapped in a neural network by a deranged clown-like manifestation of their own fears, The Doctor was selected as the crew's 'negotiator' as he was the only person who could access the network without being trapped in it. Although he initially failed to reason with the Clown, he was eventually able to trick the Clown into releasing his current "hostages" by claiming that Janeway would take their place, the crew in reality providing a fake Janeway. (VOY: "The Thaw")

In 2373, The Doctor reached the limit of his memory capacity and started suffering massive memory loss. When an alien attack injured Paris, The Doctor was unable to treat him because his program was degrading and he was beginning to lose all of his medical knowledge. When it became evident that his program would disintegrate completely, another hologram, the Diagnostic Program Alpha-11, was used to find the source of the problem. It was discovered that the problem was in The Doctor's core programing, which had become severely fragmented because of constant use of the EMH over the course of the past two years. The maximum operation for the EMH was intended for around 1,500 hours (roughly two months). To further complicate matters, The Doctor's expansion of his original programming to include personality subroutines and interests in things such as opera, interpersonal relationships with the crew and engineering skills had filled all of his available memory buffers, leaving little room for his program to operate in its intended function.

The captain was playing with the idea of reinitializing The Doctor's program, but that would have meant loss of all his memories and everything he had experienced over the past two years. Kes objected to just resetting him and asked the captain to try and find another solution. When no other options were found, Kes suggested overlaying the Diagnostic Program's programming matrix onto The Doctor's. This effectively deleted the Diagnostic program and integrated its core portions as a graft onto The Doctor's program. This procedure restored The Doctor but led to massive memory loss, including his recollection of the crews' identities and most events of the previous two years. Although some memories seemed to have survived, it was unclear if The Doctor would struggle to regain his hard-won personal skills. But some hope remained when Kes, after the reinitialization, observed The Doctor singing a song to himself; a song that was learned prior to the transfer of the Diagnostic program matrix onto his own.(VOY: "The Swarm")

Later that year, he assisted in stopping Henry Starling's plan to steal a timeship which had accidentally traveled into the past, simultaneously acquiring a mobile emitter that permitted him movement beyond the limits of Voyager's sickbay and holodeck after Starling 'stole' him from Voyager to question him about their presence in this timeline, transferring him into the mobile emitter to make it easier to threaten his existence. Having escaped Starling, the Doctor rescued Chakotay and Torres from some survivalists, returned to Voyager and enjoyed his new-found freedom from sickbay, the emitter proving simple for the Doctor to use while also allowing him to be returned to sickbay. (VOY: "Future's End", "Future's End, Part II") The Doctor was able to create a device to remove Ilari warlord Tieran's consciousness from Kes.(VOY: "Warlord") He also helped Janeway rid Voyager of an attacking macrovirus when she returned from an away mission and the rest of the crew had been infected. (VOY: "Macrocosm")

In an attempt to improve himself further, The Doctor created EMH program 4C, adding personality subroutines to his holomatrix copied from many historical figures, including Lord Byron, Mahatma Gandhi, Socrates, Marie Curie, and T'Pau. Unfortunately, The Doctor didn't realize that even great historical figures had less desirable attributes and that all those, combined within his personality, would cause his program to destabilize. As a result, The Doctor began to develop a second, darker personality which exhibited callousness, anger and deceit. He attacked B'Elanna Torres, who was trying to fix his program, and rendered her immobile so she could not tell on him. He also attacked Zahir, an alien whom Kes had befriended, and kidnapped her, trying to arrange passage to another planet. Protective of and attracted to Kes, The Doctor attempted to kill Zahir, claiming that Kes's innocence required that he be there to protect her. After the failed escape attempt with Kes in tow, The Doctor was beamed back aboard Voyager, having finally lost the added subroutines and unable to remember his actions ever since the darkening in his personality had taken over. (VOY: "Darkling")

The Doctor's holographic family

Despite such incidents, The Doctor nonetheless continued to expand his programming. In order to experience human family values, he once created a holodeck family, assuming the name of "Kenneth." Initially the program was idyllic, with a devoted, loyal wife who loved chores and serving her husband and obedient children who insisted doing their homework and fought over who would say goodbye to "Daddy" first when he left for work. The Doctor was pleased, but when he invited Kes and Torres over for dinner, Torres was more than annoyed with the "lollipops" - as she called them - The Doctor had created, stating that what he had created was in no way what a family life dynamic was like. With The Doctor's permission, Torres reprogrammed it to be more realistic. In the new simulation, his wife wasn't a devoted housewife looking forward to his bringing colleagues home for dinner and his children were rebellious, undisciplined and disobedient. The Doctor was mortified at the changes, as they were not at all what he had in mind when imagining his family. He even contemplated deactivating it permanently after his 'daughter' was fatally wounded in an accident and he could not take the pain that came with losing her. However, Tom Paris helped The Doctor learn to cope with the negatives as well as the positives in having a family, and The Doctor returned to the program to mourn the loss of his daughter with his wife and son. (VOY: "Real Life")

The Doctor proved instrumental in assisting the crew's escape after an alien race knows as the Nyrians commandeered Voyager and relocated the ship's entire crew into an artificial environment suitable for them. Chakotay, as the last crew member on board, transferred The Doctor's program into the mobile emitter before he could be deleted. Torres subsequently modified The Doctor's optical sensors, allowing him to "see" portals between artificial environments, and with the aid of another prisoner, named Jarlath, the crew reached the Nyrians' spaceship and retook Voyager. (VOY: "Displaced")

In late 2373-74, Voyager became involved in a war between the Borg and Species 8472. Janeway made a pact with the Borg for safe passage through their space in exchange for providing them with technology that could defeat Species 8472. After Harry Kim was injured in an attack by Species 8472, his cells began to be destroyed, but The Doctor used nanoprobes to cure him by reprogramming the nanoprobes to directly attack the invading cells. This treatment enabled Voyager's crew to develop a weapon that could be used against Species 8472, giving the crew a bargaining chip to negotiate a temporary alliance with the Borg. (VOY: "Scorpion, Part II")

After the alliance with the Borg ended, Janeway took in Seven of Nine, a Borg drone. The Doctor removed most of Seven's Borg implants and helped restore her to her human form. (VOY: "Scorpion, Part II", "The Gift")

Like the rest of the crew, The Doctor mourned Kes's departure from the ship, as her enhanced telepathic abilities became too dangerous for her to remain aboard Voyager. (VOY: "The Gift")

Dejaren in 2374

The Doctor and Torres answered a distress call and found a hologram named Dejaren alone on a ship. Initially The Doctor tried to befriend the hologram, sympathizing greatly with its struggles. Dejaren was eager to learn about The Doctor's freedom on Voyager, as his own crew never treated him as anything other than equipment and kept him constantly confined in one part of the ship. Eventually The Doctor and Torres discovered that Dejaren had killed his organic crew on the ship, having been driven mad by constantly being treated as a tool. After failing to convince The Doctor that holograms were a higher form of life, Dejaren tried to kill Torres and deactivate The Doctor by stealing his mobile emitter. Fortunately, Torres was able to successfully deactivate Dejaren by destabilizing his holomatrix, leaving the crew with a greater appreciation of The Doctor's personality and loyalty. (VOY: "Revulsion")

The EMH Mark II meets the EMH Mark I

The Doctor, upon his first mission to the Alpha Quadrant, was instrumental in establishing contact with Starfleet. Shortly after Voyager discovered a Hirogen communications network leading into the edge of the Quadrant, the crew attempted to send a message to a particular Starfleet vessel, the USS Prometheus, which was within range of the farthest relay. When the message failed to reach the Alpha Quadrant, however, Voyager's crew decided to send a hologram, as it was less likely to decompile before reaching its destination. With limited time to write a completely new holographic program to send through the network before the ship moved out of range, The Doctor was the only program large enough to have a chance of making it through the network intact.

When The Doctor reached the Prometheus and discovered that the ship had been taken over by Romulans, he once again claimed holographic neutrality to escape deletion. The Doctor had to activate the experimental EMH Mark II on board the Prometheus, and despite the initial conflict between the two (the Mark II apparently thought that The Doctor was defective and obsolete, while The Doctor regarded the Mark II as an arrogant new upstart), the holograms retook control of the vessel. They accomplished this by combining The Doctor's personal experience with the Mark II's detailed knowledge of the ship. Having defeated numerous Romulan warbirds surrounding the Prometheus, Starfleet officers boarded the vessel and The Doctor was subsequently able to speak directly with Starfleet Headquarters and set the record straight about Voyager's disappearance. The Doctor returned to Voyager, with welcome news that the ship was no longer alone. (VOY: "Message in a Bottle")

Later in 2374, The Doctor and Harry Kim played an important role in helping to retake the ship from the Hirogen, who were using the ship's previous crew as prey in holoprograms but had left both The Doctor and Kim free, so that The Doctor could heal the crew and Kim could work on expanding the holodecks. The Doctor was forced to treat Seven of Nine, but upon doing so he secretly added a program to her Borg components that would restore her memories during the simulation, starting a chain of events that would bring Voyager back under the control of the crew. During a Nazi program, he and Neelix persuaded the Klingons in one program to attack the Hirogen and Nazi soldiers. (VOY: "The Killing Game", "The Killing Game, Part II")

Quarren, holding The Doctor's backup module

The same year, a group of Kyrians, led by Tedran, beamed aboard the Voyager and took several people hostage. They were defeated when Tedran was killed by the Vaskan ambassador Daleth.

Several days later Voyager was attacked by nine Kyrian ships. Several troops managed to board Voyager and stole various pieces of technology before escaping, including the EMH backup module. The devastating war between the Vaskans and Kyrians that followed was called The Voyager Encounter, as the official records were altered to portray the Kyrians as the victims and Voyager as the aggressors.

Seven hundred years later, a backup copy of The Doctor's program was reactivated in the Kyrian Museum of Heritage by Quarren and blamed for war crimes the crew of Voyager didn't commit. The Doctor explained the true history of the Kyrian/Vaskan conflict, and although this caused old tensions between the two races to once again flare up, it led to a new understanding between them and eventually created a harmonious society.

This copy of The Doctor became the Kyrian Surgical Chancellor for many years after these events. Eventually, however, he left his post in a one-person ship with the aim of reaching the Alpha Quadrant, claiming that "he had a longing for home". (VOY: "Living Witness")

In an attempt to save Torres, who had a cytoplasmic lifeform attached to her, The Doctor called upon a holoprogram of a Cardassian named DoctorCrell Moset, a renowned exobiologist in the Alpha Quadrant. Bajoran crew member Ensign Tabor informed Janeway and The Doctor that Moset had committed war crimes during the Cardassian occupation ofBajor and that he was personally responsible for the death of his father. This caused a controversy on board, as Tabor and others demanded that Moset's program be put offline and decompiled and his research obliterated altogether or else they would resign their commissions. The Doctor, unaware of Moset's reputation, was at first unwilling to delete the program and refuse Moset's help, and eventually used it to save Torres. However, as pressure from all sides kept building up and as he himself discovered that Moset's actions were unethical, he deleted the Moset program from all of Voyager's files. (VOY: "Nothing Human")

That same year, The Doctor experienced a deep personal crisis of his own: He found out that memory files pertaining to an EnsignAhni Jetal had been deleted from his program. When he confronted the crew, they reluctantly told him what had happened. Harry Kim and Jetal had been seriously injured during an away mission a few months earlier. Because The Doctor could not perform life-saving surgery on both patients simultaneously, he was forced to pick one patient, knowing that the person he was unable to treat would die. In a split-second decision, The Doctor decided to operate on Kim, thus indirectly allowing Jetal to die. Shortly after, The Doctor fell into a deep ethical crisis, questioning his decision to treat Kim and not Jetal, even though their injuries were equally fatal. He blamed himself over and over again for having been biased and helping his friend rather than Jetal, whom he was not as close to. He became caught in a loop of constantly questioning his decisions to the point where he broke down completely, unable to function. The captain decided that it would be best if the memories of Jetal and the incident be deleted. However, the truth did come out and as soon as The Doctor found out, the same pattern emerged and he found himself struggling with the same dilemma once again.

After Seven pointed out that they should not treat The Doctor like a piece of equipment but instead like the individual he had become, the captain decided that this time, instead of deleting his memories, they would stand by him and try to help him in this crisis, just as they would a friend or any other flesh-and-blood member of the crew. Janeway helped him accept his decision and realize that part of being an individual is making tough decisions and learning to live with them. (VOY: "Latent Image")

Later that year, The Doctor tried to give Seven of Nine social lessons on how to date. During their sessions he became quite infatuated with her, but could not bring himself to admit his feelings. He also had a small wager with Tom Paris, who had told The Doctor that Seven was incapable of going on a date without causing an incident. The Doctor told Tom that he would prove him wrong in exchange for doing a full month of sickbay duty. When Seven found out about the wager, she was disappointed in The Doctor, but she forgave him later when he apologized. When Seven told The Doctor that she no longer needed the lessons as there were no suitable mates for her on board, The Doctor was crushed about Seven's obviously not reciprocating his feelings, and he returned to the holodeck for a lonely rendition of "Someone to Watch over Me". (VOY: "Someone to Watch Over Me")

In 2376 an artificial intelligence was found on a planet and the crew discovered that it was a weapon sent on a mission of destruction. The machine interfaced with The Doctor's matrix and took it over. It threatened Voyager to take it to its target. Eventually it was convinced that its mission had been an accident; its systems had been triggered by a computer error and a target had merely been selected at random. Transferring its intelligence out of The Doctor, it was beamed off Voyager and destroyed other war machines on the same obsolete mission. (VOY: "Warhead")

Early in the year, The Doctor was investigating the USS Equinox and was disabled by that ship's EMH, who stole his mobile emitter and returned to Voyager, posing as him.

Later, when he was reactivated by Captain Ransom, his ethical subroutines were deactivated to coerce him into extracting information from Seven of Nine.

After he was restored to himself and escaped to Voyager, Seven offered to add security measures to his program to prevent further tampering, assuring him that she bore him no ill will (she even "teasingly" informed him that he was off-key when he sang to her as he tapped into her implants). He also deleted the Equinox EMH upon returning to Voyager, although the Equinox EMH tried unsuccessfully to threaten him with holographic bombs. (VOY: "Equinox", "Equinox, Part II")

A celebration for The Doctor as he receives the Starfleet Medal of Commendation

Captain Janeway awarded The Doctor the Starfleet Medal of Commendation for his part in repelling raiders who wanted to strip Voyager of essential components. This predicament was both incited and resolved successfully thanks to The Doctor's experimentation with introducing daydreaming to his program; the aliens hacked into The Doctor's program, but due to his daydreams, they were given an exaggerated image of Voyager's defenses and were tricked into retreating. In light of his accomplishments, Captain Janeway gave permission for research into the creation of an Emergency Command Hologram, to take command of the ship if the senior staff were ever immobilized. However, he was left more than slightly embarrassed by the fact that several of his daydreams featured Janeway, Seven, and Torres competing for his affections (as well as one where he painted Seven in the nude), although Janeway assured him that it was only human to fantasize. (VOY: "Tinker Tenor Doctor Spy")

The Doctor played the part of the village priest, Father Mulligan, in the Fair Haven program. When he tried to free Kim and Paris from the townsfolk, who believed they were evil spirits, he himself was captured. The townsfolk decided to hypnotize him for answers. The Doctor was highly skeptical; however, they managed to successfully hypnotize him after taking his mobile emitter away. Pressed to reveal his true name, he admitted that he "had not decided on one yet." (VOY: "Fair Haven", "Spirit Folk")

Due to a time differential, The Doctor was sent to a planet with a tachyon core as, being a hologram, it wouldn't affect him. Due to problems, The Doctor spent three years on the planet, during which time he gathered information on its geologic problems, lived in an apartment with a roommate, and had a son named Jason. How he had a son is unclear, as he only said it was a long story, but when an astronaut returned to the planet to enlist their help in freeing Voyager, The Doctor requested that a message be passed on to his son's family. (VOY: "Blink of an Eye")

While encountering the Qomar he began singing, which awed the aliens, as they had no concept of music. He gave a recital on the planet. They asked him to stay, and he considered resigning his post as Voyager's chief medical officer to pursue a full-time career on Qomar. However, upon revisiting the planet, he discovered that the Qomar had made what they considered a superior holoprogram (in that it could sing notes outside the human vocal range) and that he was not wanted. He returned to Voyager, depressed at how his musical career had ended and embarrassed at his earlier actions, but a final piece of fan mail from Seven assured him that he was still appreciated on Voyager. (VOY: "Virtuoso")

When Voyager encountered con artists posing as Janeway, Tuvok, and Chakotay in an attempt to make money, The Doctor proved instrumental in the recovery of the stolen property. After tricking Dala, one of the con artists, into boarding the Delta Flyer, The Doctor and Tom Paris knocked her out. The Doctor subsequently altered his holographic matrix so that he resembled Dala, allowing him to confront the other two con artists and learn where they had concealed their stolen property before turning them over to the local authorities. (VOY: "Live Fast and Prosper")

The second mission to the Alpha Quadrant occurred when Lewis Zimmerman was dying and The Doctor requested to be transmitted back to the Alpha Quadrant to help treat him. While he was at Jupiter Station, Lewis Zimmerman fought The Doctor and his treatment, regarding The Doctor's presence as an unpleasant reminder of his failure with the Mark I as a whole. This caused Reginald Barclay to contact Deanna Troi to help out with the situation. Neither the counselor nor Barclay could make either doctor reach any sort of agreement, as both of them were too stubborn to back down. It wasn't until The Doctor began to decompile that Lewis Zimmerman corrected the error and the two reached a mutual understanding that bordered on a father/son relationship. This was mainly reflected in a conversation where The Doctor admitted that he'd hoped Zimmerman would be proud of his accomplishments if they ever met, and Zimmerman confessed that he was grateful that at least one EMH Mark I was still doing what he had designed them for. The treatment worked, and shortly before The Doctor left for Voyager, Zimmerman told The Doctor that he could call him next time Voyager was given a chance to communicate with Earth. (VOY: "Life Line")

During the last year of Voyager's journey home, The Doctor's program was stolen and sold to Dr. Chellick, who was in charge of a medical hospital on the planet Dinaali. The Doctor was appalled at the medical malpractice that was taking place. Only the rich or useful were accorded the best medical care, while others were left to die or denied medicine because of their social standing. Along with a few medical personnel, he helped change the situation, although he suffered an ethical crisis afterward. In order to convince the staff to change procedure, The Doctor had deliberately infected Chellick with a potentially fatal virus. Because Chellick was classified as a lower grade patient, he was forced to change his normal procedure to save his own life. (VOY: "Critical Care")

Seven of Nine and The Doctor became one when, in order to hide his matrix from aliens who hunted and destroyed holograms, he was downloaded into her cybernetic implants. He experienced the human feelings of taste and touch for the first time. Seven became angered at his 'abuse' of her body while he was in charge of her functions. The Doctor felt Seven showed excessive restraint and did not allow for superfluous pleasure, a thing that The Doctor thought was an important part of life. After they returned to Voyager, however, Seven seemed to better understand his point of view, bringing a meal to sickbay and describing the sensations of eating it to The Doctor to allow him to continue to experience it. (VOY: "Body and Soul")

When Voyager responded to a Hirogen distress call, the crew found that the holograms created as victims for Hirogen training had turned against the hunters. A group of these holograms had escaped to a ship and later kidnapped The Doctor. He discovered the holograms were just trying to find somewhere where they could live in peace. Eventually agreeing to help them, he escaped with them and took Torres to help the holograms set up a civilization of their own.

Iden in 2377

However, the holograms, led by Iden, took extraordinary measures to achieve their freedom, even going along with Iden's plan to attack and eventually destroy a mining vessel to obtain and "liberate" fellow holograms. The Doctor's suspicions about Iden were confirmed when he admitted he wished to start a new religion, with himself as the "Man of Light" having freed numerous holograms in various and often violent fashions, considering all organics as being the same despite the Doctor's protests, believing that B'Elanna displayed her prejudices when she stated that three holograms Iden had just 'liberated' were simply too basic to maintain sentience. Eventually the Doctor had to destroy Iden to protect everyone else. Ashamed of his actions, he volunteered to turn in his mobile emitter, but Janeway assured him that nobody blamed him for doing the human thing and making a mistake in judgment. (VOY: "Flesh and Blood")

Shortly after this, The Doctor discovered that B'Elanna Torres was pregnant with Paris's child. At first Torres tried to reprogram The Doctor to alter the child's DNA and remove the Klingon traits, fearing a repeat of her own upbringing. While growing up she believed her father had left because he couldn't handle two Klingon women. After talking with her, Tom Paris eventually convinced Torres that he would love their children no matter what they were like and he hoped that every one of them would be just like her. After apologizing to The Doctor for reprogramming him, Torres asked him to be the child's godfather and he willingly accepted. (VOY: "Lineage")

When the crew was forced to transport alien prisoners to a distant planet where they would be executed for their crimes, The Doctor was appalled at the death penalty rule enforced by the planet. He also discovered that Iko, one of the patients, had actually been born with a brain defect that left him prone to violence. Using Seven's nanoprobes, The Doctor managed to cure Iko of this defect, effectively restoring Iko's conscience and making him a new person. Iko's appeal was, tragically, rejected, but The Doctor and Seven were able to take some small measure of comfort in knowing they had helped him. (VOY: "Repentance")

When Voyager was abandoned due to tetryon radiation flooding, Captain Janeway activated the ECH for the first time, allowing The Doctor to repair damage to the ship while the crew waited in the escape pods for Voyager to be declared safe once again. The Doctor managed to defend the ship against scavengers and had begun enacting repairs by the time Chakotay and Kim, who had been on an away mission, returned to the ship. The Doctor further demonstrated his command abilities by utilizing a photonic shockwave to disable two Quarren ships. While repairing the ship along with Ensign Kim, they frequently conflicted regarding the impromptu chain of command – while Kim was actually a commissioned officer, The Doctor was programmed with the experiences of renowned commanders throughout history. Harry's strategy saved the ship from attack, and The Doctor was forced to admit that he lacked the valuable practical operational experience of other officers. He made peace with Harry before returning to his normal role as Chief Medical Officer. (VOY: "Workforce", "Workforce, Part II")

After an away team became trapped on a planet with a toxic atmosphere, The Doctor was part of a rescue that was launched. The Doctor almost single-handedly rescued the entire team when he dressed as a native and infiltrated the native's caves. He explained that since he was a hologram, the radiation had no effect on him, and he was able to effectively disguise himself as part of the plan. Later on Voyager, he treated a baby infected with radiation poisoning and cured him and a native with the help of Seven of Nine. (VOY: "Friendship One")

The Doctor activated his command subroutines again in 2378 in an attempt to rescue Captain Janeway from the aliens who had kidnapped her. His holographic matrix altered to allow him to pose as various members of the crew, such as Janeway, Torres, and Chakotay. The Doctor was eventually able to evacuate Engineering and activate the ECH program. As the Emergency Command Hologram, The Doctor had the authorization to ejectVoyager's warp core; he then tried to free the captain by exchanging the core as ransom. He was able to rescue Janeway and recover the core, but when the excess subroutines inserted by the aliens nearly caused his program to collapse, he made several embarrassing "deathbed" confessions including his love for Seven. Having recovered, he subsequently spent a whole week in sickbay out of sheer embarrassment but was eventually convinced by Janeway to rejoin life on the ship. (VOY: "Renaissance Man")

He returned to Earth when Admiral Janeway changed the timeline by going back in the past and helping Voyager return to Earth sooner than the twenty-one years it originally took. During that time The Doctor was treating Lt. Commander Tuvok's degenerative neurological disease, but kept it quiet at Tuvok's request. The Doctor's last action on the ship was to help deliver his goddaughter, Miral Paris, while in the Borg transwarp hub. As the crew were contacted by Starfleet ships, The Doctor alerted Miral's father that "There's someone here who'd like to say 'Hello'." (VOY: "Endgame")

The Doctor took a keen interest in opera, frequently practicing his singing with a holographic soprano. (VOY: "The Swarm")

Seven of Nine helped with The Doctor's singing capabilities when, while being held against her will on the USS Equinox, she noticed his vocal modulations deviated by 0.30 decihertz. When they returned to Voyager, she informed him of this fact and he agreed to meet her on the holodeck: "Just you, me and a tuning fork." (VOY: "Equinox, Part II")

The first of a number of names chosen by The Doctor in honor of great medical figures of Earth's past. In this case, the name was used in order to interact with Freya and other characters in Harry Kim's holographic recreation of the poem Beowulf; following Freya's "death", where this name was the last thing she said to him, the Doctor discontinued using the name, finding the association with her too painful to bear.

Singing was not the only creative outlet for The Doctor. He worked hard to create a holographic novel called Photons Be Free, based on an EMH on the starship Vortex and the treatment he faced from the organic members of the crew. The characters and the environment were strongly based on the crew of Voyager. After discovering his friends were concerned about his interpretation of them, he agreed to change it despite the weeks of work involved.

His publisher didn't appreciate the delay and so published the original version. In an argument with the publisher, The Doctor was told he had no rights: although he might be the author, as a hologram he wasn't a sentient being. During the subsequent debate, Janeway, Tuvok, Seven, Barclay and Kim spoke on The Doctor's behalf. Tuvok pointed out that The Doctor had created an original piece of work; Seven explained how The Doctor helped her develop as a person; Barclay compared The Doctor's aid to Zimmerman as a son seeking his father's approval; Kim explained how the Emergency Command Hologram subroutines represented a human desire to change; and Janeway cited The Doctor's defiance of her orders as a human action, something that a mere hologram - designed to obey orders - couldn't have done. At the conclusion of the 'trial', The Doctor, though not deemed a "person" at the time, was found to have the same rights as a non-holographic author and was allowed to recall the original version of the holonovel in favor of the new one when it was ready. The judge further urged The Doctor to continue his fight for sentience upon his return to Federation space. (VOY: "Author, Author")

At first, family life was blissfully perfect until B'Elanna Torres "visited" the family at home and found them to be unrealistic. She altered the program, adding randomness and "realism". As a result, his teenage son Jeffrey became rebellious and began to hang out with some unsavory Klingon youths. In addition, he argued with Charlene and lost the formerly close bond he had possessed with Belle. Upon Belle's Parrises squares accident, the family came together.

Comforting Belle

Initially apprehensive about losing her, The Doctor was persuaded by Tom Paris not to delete the program after this incident, but to work through her death with his remaining family. (VOY: "Real Life")

In 2373, Voyager encountered the Aeon under command of Captain Braxton. Due to a temporal paradox, Voyager was transported to Earth in 1996. During this mission The Doctor obtained a piece of 29th centurytechnology from Henry Starling, originating from the Aeon, called a mobile emitter. This device, though only a few centimeters long, was able to contain the entire EMH program and project The Doctor autonomously. After the timeline was restored and Voyager returned to the Delta Quadrant, The Doctor kept the emitter. It was quickly established that the transfer of The Doctor's program to and from the emitter would be quite easy; practically all he had to do was issue a voice command and attach the emitter to his left shoulder.

This device proved to be of vital importance and saved the crew of Voyager on numerous occasions. One of the most notable times when the emitter proved useful was shortly after The Doctor had acquired it. He helped Captain Janeway fight off a swarm of macroviruses that had infected the ship; since Janeway had been away at the time, and The Doctor (as a hologram) was naturally immune to the virus, they were forced to stand alone to save the crew. (VOY: "Macrocosm") The emitter also allowed The Doctor to help crew members all over the ship, which was especially useful after Kes left a short time later. (VOY: "The Gift")

The mobile emitter helped The Doctor to watch over the ship while the crew was in stasis during a trip through a radioactive mutara classnebula. While proving to be helpful in allowing The Doctor to help Seven of Nine during this situation, the nebula affected the mobile emitter damaging its electro-optic transmitter. The Doctor, later, linked the emitter to the EPS relay network. For some time, this worked, until the EPS relays started to fail, after which the emitter went offline. (VOY: "One")

Due to a transporter accident, the mobile emitter was combined with some of Seven of Nine's nanoprobes. This, combined with Ensign Mulchaey's DNA, created a new Borg drone with 29th century technology and the mobile emitter intact as an integral part of its central nervous system. This drone called himself One and eventually sacrificed himself in order to save the crew of Voyager. Afterward, the mobile emitter was salvaged and returned to The Doctor. (VOY: "Drone")

On some occasions the emitter was stolen from The Doctor and/or used by rogue programs, such as Dejaren, Iden, and the reprogrammed EMH Mark I of the USS Equinox. (VOY: "Flesh and Blood", "Equinox, Part II") On all occasions however, The Doctor was able to recover the emitter with no apparent side effects to his program. The mobile emitter was also used by a version of The Doctor that had corrupted files after he had attempted to improve his personality. (VOY: "Darkling")

Other notable occasions where the emitter was used by holograms other than The Doctor were when the Leonardo da Vinci hologram was transferred to it after both the emitter and main computer core were stolen in a transporter attack (VOY: "Concerning Flight") and when The Doctor loaned the emitter to the Barclay hologram that had been received in a data stream. (VOY: "Inside Man") Michael Sullivan also used it to be transferred out of the holodeck and onto Voyager's bridge, believing the emitter to be a charm to get into the spirit world. (VOY: "Spirit Folk")

While starting out as nothing more than a piece of equipment intended to provide a short-term supplement for the existing medical team, the Doctor went on to form far greater bonds with the rest of the Voyager crew as time went on. Thanks to Kes's initial efforts to encourage him to assert himself as a person rather than a machine, the Doctor gained control over his own activation code and was accorded all the respect and authority of a biological chief medical officer, save for the obvious detail that he remained in sickbay rather than being granted his own quarters even after the acquisition of the mobile emitter gave him the opportunity to exist outside of sickbay. The respect he received among the rest of the crew for his role as medical officer was so great that the entire crew twice sacrificed opportunities to communicate with their families so that the Doctor could deal with personal business, once when he requested that he be transmitted back to the Alpha Quadrant to try and treat the dying Lewis Zimmerman (essentially the closest person he had to a father) despite this preventing any other messages being sent back for another month, and a second time when the senior staff used their daily eleven minutes of contact with Earth to hold a court case that would determine whether the Doctor was entitled to legal rights despite his holographic status.

Kes was one of The Doctor's first friends on board Voyager and over the course of her stay aboard the ship, the two bonded considerably. Their friendship began early in the first year after Kes displayed great interest in medicine. This interest led The Doctor to commence training her, which brought them close as colleagues. (VOY: "Phage") Kes was able to quickly study the works given by The Doctor, which greatly intrigued him. Although The Doctor exhibited a terrible bedside manner and had a personality that wasn't pleasing to the rest of the crew, he reacted more kindly to Kes, treating her as a colleague and friend. (VOY: "Eye of the Needle") Kes in turn was always very encouraging of The Doctor, insisting that he was more than a projection and that there was no reason why he could not exceed his original programming. Kes's care for The Doctor evidently had a powerful effect on him; when his program suffered damage in 2372 and he began to hallucinate that he was his creator, Dr. Lewis Zimmerman, his hallucination included a human Kes as his wife. In that simulation, The Doctor confessed to Kes that he always found her to be beautiful during a time when 'Lewis' appeared to be 'dying'. After The Doctor's program was recovered, he told Kes about his hallucination. Kes promised to keep what he had told her between them in case Neelix found out in another bout of jealousy. (VOY: "Projections")

However, romance between the two never developed, and The Doctor and Kes settled into a father/daughter relationship, with The Doctor becoming Kes's teacher and mentor during her time as a medical student and assistant. Kes's trust in The Doctor was so great that she asked him to perform the rolissisin- a ritual usually performed by the daughter's father shortly before conception- on her. (VOY: "Elogium")

Kes persuaded Janeway that The Doctor should be given more respect and consideration by granting him some authority over his deactivation code, a significant step towards being regarded as a full member of the crew rather than a piece of equipment. Kes always encouraged The Doctor to embrace and develop his personality, and she helped him become part of the crew. At a time when The Doctor was believed to be nothing but a program based on another program without the capacity of independent decision making, she told him that there was no difference between how he accessed his programs and made decisions for medical treatments and how she, a flesh and blood being, made decisions based on information stored inside her brain. Kes also encouraged him to pick a name and advised him when he had desperately fallen for Danara Pel but did not know how to handle those emotions. All these encouragements helped The Doctor to realize his potential. (VOY: "Lifesigns", "The Swarm")

The next year Kes helped save The Doctor's matrix when, due to his program having been active far longer than it was designed for, he began to lose his memories and skills as a physician. After Torres activated a hologram of Dr. Lewis Zimmerman, he explained that The Doctor had been online too long and was deteriorating. Kes persuaded Zimmerman to graft his matrix onto The Doctor's, restoring his mental capabilities. (VOY: "The Swarm")

Later that year, when The Doctor's program developed a secondary, evil personality as a result of his experimenting with his personality subroutines, the 'Dark Doctor', despite his deep resentments, still appeared deep down to care for Kes, albeit in a more twisted fashion than the normal Doctor. Not only did he try to kill Zahir, the alien whom Kes had developed feelings for, but he also claimed, during his capture of her, that she needed his help and protection because she was naive. (VOY: "Darkling")

The Doctor was responsible for the removal of Seven's implants and also conducted her weekly maintenance sessions. He also took it upon himself to teach Seven social behavior, using the same interpersonal relationship exercises Kes once practiced with him. (VOY: "Prey") Later, he created a holodeck simulation of Voyager for her to become more comfortable with large social gatherings. (VOY: "One")

The Doctor encouraged Seven to explore romantic relationships in 2375. He coached her in the basics of dating and grooming, using a lesson plan entitled "Love Amid the Stars". He also discovered her singing voice and the two sang a duet of "You Are My Sunshine". He was partially motivated by a wager made with Ensign Paris, who believed that Seven would not be able to bring a date to a reception planned aboard Voyager without making a scene. Although Seven's date with Lieutenant Chapman ended in disaster, she attended the reception with The Doctor and charmed the guests with a toast to individuality. However, she was hurt to discover that The Doctor's help was due to the bet. At this point, The Doctor found himself falling in love with Seven but refused to admit it to her. He tried to apologize to her but she came to him first and said she no longer needed the lessons in romance, because there were no suitable mates aboard. The Doctor was very disappointed that Seven did not reciprocate his feelings. (VOY: "Someone to Watch Over Me")

In 2376, while The Doctor was stranded aboard the USS Equinox along with Seven, the crew disengaged his ethical subroutines to extract activation codes for their warp drive from Seven's cranial implants, which would leave her mentally disabled. The Doctor almost went through with the procedure, but Captain Rudolph Ransom stopped him. He apologized to Seven for the incident and she held no ill will towards him. (VOY: "Equinox, Part II")

The Doctor created a subroutine for daydreaming in early 2376. Seven featured prominently in several fantasies, either serving as a damsel in distress or competing with other female Voyager crew members for The Doctor's affections. He even fantasized about painting her in the nude. When the fantasies began to overrun his program, his mental activity was tied into the holodeck, allowing Seven to see what he had been daydreaming. She did not take offense but after she kissed him following Captain Janeway's announcement that the Emergency Command Hologram subroutines would be developed, she made it clear that it was simply a platonic gesture. (VOY: "Tinker Tenor Doctor Spy")

The Doctor as Seven of Nine

While Ensign Kim, Seven and The Doctor conducted a routine survey on board the Delta Flyer in 2377, they were captured by a race known as the Lokirrim. The Lokirrim had waged war against holographic lifeforms who rebelled against Lokirrim rule, and as a result they banned all holographic activity within their borders. Seven transferred The Doctor's program to her cortical implant in order to hide him from the Lokirrim and prevent him from being decompiled. In the process The Doctor took control of Seven's motor abilities and was essentially trapped in her body. The Doctor tried to engineer an escape by cultivating a relationship with a Lokirrim official, Ranek, but the new sensations of taste and emotion were too tempting for The Doctor. He ended up overindulging in several foods and causing pain to Seven. Ranek later called Seven to the ship's bridge with the intention of setting up a romantic liaison. Although The Doctor was able to see his command codes, Ranek attempted to kiss him in Seven's body. Shortly afterward, he went to complain about the incident to Jaryn, a crewwoman whom The Doctor had been working with to treat injured Lokirrim crew. The Doctor became sexually aroused when Jaryn gave Seven a neck massage. Both incidents greatly irritated Seven, and once he had been returned to the mobile emitter, they got into an argument about the value of indulgence. The Doctor felt Seven showed excessive restraint and did not allow for superfluous pleasure, which he believed was an important part of life. Kim managed to return the subject to escape, and The Doctor and Seven worked together once again to transmit a distress signal to Voyager. The Doctor was downloaded back into Seven's implants and was able to convince Ranek to join her on a second date. They knocked him out at the first available opportunity and transmitted a message to Voyager including the ship's command codes. Their plan was discovered by Jaryn and Seven was taken captive. After Voyager arrived, Seven returned The Doctor's program to the mobile emitter and they escaped. Upon their return to the ship, Seven decided that The Doctor had a point about her restraint concerning pleasures such as food. She brought a meal to sickbay and described the sensations of eating it to him, allowing him to experience it vicariously. (VOY: "Body and Soul")

When The Doctor's rights as an individual came into question, Seven testified at the hearing conducted with Starfleet Command. She spoke highly of The Doctor, appreciative of his efforts to help her develop individuality. (VOY: "Author, Author")

In 2378 when The Doctor believed he was about to die, he finally admitted his feelings for her and was embarrassed when he survived. (VOY: "Renaissance Man") The Doctor was also crestfallen when he learned Seven had begun to date Chakotay. (VOY: "Endgame")

Although their relationship was often a difficult one, The Doctor also managed to become close friends with Paris, who affectionately referred to The Doctor as "Doc" on several occasions. One of the key points in their friendship was the fact that it was Paris who helped The Doctor explore one of the most difficult aspects of being a member of the crew: relationships. When The Doctor was initially rejected by Danara Pel, he went to Paris for relationship advice and Paris helped set The Doctor and Denara up on a date in a holoprogram, informing The Doctor that his current approach to women was all wrong. (VOY: "Lifesigns") When The Doctor created a holographic family and one of his 'children' faced death after an accident, it was Paris who convinced The Doctor to keep running the program rather than shut it down, realizing that The Doctor needed to experience the negative aspects of family life if he wanted to develop as a person. (VOY: "Real Life")

After Kes's departure from the ship, Paris was chosen as The Doctor's new medical assistant, serving as Voyager's CMO when The Doctor was unavailable. Over time it became clear that, although he complained about the role, he still wanted The Doctor's respect as a person. This was the main reason Paris resented The Doctor's holonovel about abused holograms, Photons Be Free; he worried that 'his' character, a womanizer called Lieutenant Marseilles who cheated on his wife, reflected how The Doctor saw him. Despite this, when the crew arranged a trial to determine The Doctor's legal rights after his publisher released the novel ahead of schedule, Paris objected to Tuvok's suggestion that they claim that The Doctor had no right to sell the holonovel in the first place, as they would basically have been admitting that The Doctor was not a real person. (VOY: "Author, Author")

As the crew's journey unfolded, Janeway soon found herself becoming friends with The Doctor, despite initially regarding him as just another hologram. The Doctor also initially disliked Janeway, making several notes on what he regarded as her more 'questionable' command decisions before he fully came to regard himself as part of the crew. As the journey unfolded however, the two of them became closer, particularly when Janeway and The Doctor were the only two crew members standing between Voyager and the macrovirus that was attacking the ship. (VOY: "Macrocosm")

As the journey went on, the two of them also began to develop an almost mother/son relationship, with The Doctor often coming to Janeway when he needed personal advice or information about how his program was developing, as well as consolation about any wrong decisions he had made in recent times. Janeway stopped The Doctor from deleting the additional subroutines that made him unique when he felt responsible for a death (VOY: "Retrospect"). Janeway assured The Doctor that none of the crew thought any less of him when he was embarrassed about the fantasies created by his daydream program, (VOY: "Tinker Tenor Doctor Spy") and Janeway told The Doctor that none of the crew blamed him for betraying them to try and help a crew of holograms. (VOY: "Flesh and Blood") As well as that, when Janeway faced death after being captured by an alien species, The Doctor risked everything to save her. (VOY: "Renaissance Man")

Although their two-way doctor/patient relationship (the Doctor treating B'Elanna's injuries while B'Elanna 'treated' any damage sustained by his program) could be difficult at times, The Doctor and B'Elanna went on to develop a surprising friendship and working relationship, such as when the two brainstormed possible solutions to help reactivate Automated Unit 3947 when he was recovered and his power was running out. B'Elanna also helped The Doctor gain a better understanding of his new mobile emitter after he acquired it, clearly expressing her fascination with the new technology. A particularly dark period for the two was when The Doctor attempted to remove a cytoplasmic lifeform from B'Elanna using knowledge acquired from the hologram of Crell Moset, a Cardassian doctor who had committed various war crimes. Although B'Elanna's feelings were hurt when the Doctor dismissed her musical opinions while preparing to give a concert for the Qomar, she later convinced him not to reprogram himself to reach the high notes achievable by the Qomar's new hologram because he would be sacrificing his identity for others if he tried to reprogram himself in that manner. Their relationship became so close that, when B'Elanna learned that she was pregnant, she asked The Doctor to be the child's godfather, and even when faced with the possibility that she could give birth to the child on Earth in Starfleet Medical, she made it clear that she wanted The Doctor to be the supervising physician rather than some stranger. (VOY: "Prototype", "Future's End, Part II", "Nothing Human", "Virtuoso", "Lineage", and more)

In 2372, The Doctor encountered the Vidiian doctor Danara Pel and developed romantic feelings for her. She gave him the name Shmullus, after her uncle who always made her smile. When they met again later that year, Denara again called The Doctor "Shmullus," although he never used the name despite his fondness for it. (VOY: "Lifesigns", "Resolutions")

Later that year Voyager became trapped in orbit around a planet where time advanced at a much faster rate than normal. The Doctor determined that the transition into this accelerated timeframe could be fatal to a humanoid and so volunteered to transport to the surface himself. It was intended that he would only spend three seconds on the planet which equated to around two days on the surface but attempts to transport him back to Voyager failed. Chakotay guessed that The Doctor would spend his time in the city's cultural center and he was located a short time after being transported down. However, to The Doctor, he had spent three years on the surface. He met a woman named Mareeza, whom he later described as his "roommate", and had a son named Jason Tebreeze. (VOY: "Blink of an Eye")

It is not clear how The Doctor, a hologram, could have fathered a child. According to the short story "Eighteen Minutes" in the book Distant Shores, The Doctor met her while she was pregnant and, being the only one to take care of her, was named the father.

Various miniature copies of The Doctor were created by the Qomar due to their admiration for the Doctor's singing. (VOY: "Virtuoso")

Harry Kim and Seven of Nine projected The Doctor's daydreams into the holodeck in order to better understand what was malfunctioning. In this daydream, The Doctor wore a painter's smock and beret while he painted a holographic representation of Seven in the nude. (VOY: "Tinker Tenor Doctor Spy")

After he stole The Doctor's program, Gar left a copy – created from one of The Doctor's old training files – aboard the starship to cover his tracks. (VOY: "Critical Care")

In 2378, Seven recreated the crew of Voyager to perfect her social skills, including The Doctor. (VOY: "Human Error")

In the possible future that Kes experienced when she began to travel backwards in time, The Doctor was offline for months during the "Year of Hell" conflict. When his program was restored, The Doctor developed a full head of hair, chose the name "Doctor Van Gogh" (although he briefly thought about calling himself Mozart) and tried to develop a means of extending Kes' life via use of a bio-temporal chamber which triggered her jumps back through time. Subsequently – or previously, depending on perspective – The Doctor of the present cured her of her sudden jumps back in time and this timeline never came to pass. (VOY: "Before and After")

In an alternate timeline where Voyager crashed into an ice planet while attempting to reach Earth via the use of a quantum slipstream drive, The Doctor's program was recovered fifteen years later by Chakotay and Harry Kim, who had been in the Delta Flyer when the crash took place, the two managing to reactivate sickbay's holographic emitters long enough to transfer the Doctor into his mobile emitter. With The Doctor's help, they managed to devise a means of transmitting information back in time to Seven of Nine's cortical implant before Voyager was destroyed, hoping to save the crew by stabilizing the slipstream and allowing them to reach Earth. After the attempt failed, it was The Doctor who made a tearful, defeated Kim realize that Voyager's salvation lay outside the slipstream, and to use the link to end the flight rather than prolong it; if they couldn't get Voyager home, they could at least save the ship and her crew. With the Flyer's warp core about to breach and rapidly running out of power to send the data, The Doctor volunteered the use of his emitter as a power source. Kim wished The Doctor goodbye before removing the emitter. This timeline was erased when Kim, moments before the Flyer exploded, successfully transmitted the data to Seven of Nine that would shut down the slipstream drive, with a message from Harry to his past self the only trace left of that history. (VOY: "Timeless")

When Voyager was fractured into multiple different time periods, sickbay reverted to Stardate 49624, a year prior to the acquisition of the Mobile emitter. Despite his relative 'youth', the Doctor of this time period was able to devise a chroniton-infused serum that would stabilize the temporal instability experienced by Commander Chakotay after the initial accident, as well as allow him to travel between the fractured time periods of the ship. Once he learned what had happened from Chakotay, the Doctor provided him with more samples of the serum, allowing Chakotay to 'recruit' Janeway from a time before Voyager was sent to the Delta Quadrant, with this Janeway being surprised when she met the Doctor and witnessed his level of development compared to the original EMH program. When Chakotay's plan was able to undo the original accident, the timeline was altered so that the Doctor never experienced these events (VOY: "Shattered").

In the aborted timeline where Voyager took 23 years to return to the Alpha Quadrant, two weeks prior to the ten-year anniversary of the ship's return, The Doctor married a Human woman named Lana and even took the name of her grandfather, Joe. He remained the personal physician of Admiral Janeway, who credited her fine health to his exceptional care over the years, and continued to visit Tuvok to monitor his neural degradation. (VOY: "Endgame")

In several early first-seasonStar Trek: Voyager scripts, call sheets, and shooting schedules and during the pre-production phase, the character of The Doctor was referred to by name as "Doc Zimmerman" after Herman Zimmerman, since the show's producers had not yet decided to leave him unnamed. (VOY Season 2 DVD trivia text version of "The 37's") The Doctor is one of two ongoing characters in science fiction who are referred to by this title, as opposed to a proper name; the other is the protagonist of the long-running British television series Doctor Who.

In the first draft script for VOY: "Caretaker", The Doctor was initially referred to "as a holographic man in a Starfleet medical uniform [....] He has no name for now... but we will get to know him in time as Doc Zimmerman. His manner is colorless, dry."

In the Special Features on the Voyager DVD collection, actor Robert Picardo mentions that he ad-libbed during his audition for the role of The Doctor, adding the line, "I'm a doctor, not a lightbulb," at the end of his script; he says that he "got a laugh" from the assembled studio executives, even though ad-libbing isn't something that's generally done on a Star Trek production. The Doctor was thereafter played by Picardo. The part of The Doctor disguised as a Hierarchy overlooker, in the episode "Renaissance Man", was played by J.R. Quinonez (see also: Roles with multiple performers).

Many people, including Robert Picardo himself, were initially opposed to Brannon Braga's idea of the mobile emitter, believing The Doctor's limitations to be one of the appeals of the character. However, Picardo relished the opportunities for growth of his character due to The Doctor's new-found mobility, without noticing any negative impact to his appeal to the fans; Picardo subsequently apologized to Braga. (Star Trek: Voyager Companion, p. 452)

Many fans have wondered if Robert Picardo actually did all of his singing himself. To answer that question, Picardo said, "I did all of my singing except for the second half of 'Virtuoso'. The Don Carlo duet and Rondine al Nido are voiced by an opera singer, Augostino Castellnano (I hope I spelled that correctly). He's a terrific guy. I simply couldn't sing high enough or well enough to pull them off, but I did my own singing in 'The Swarm', 'Tinker, Tenor...', 'Renaissance Man', 'Someone to Watch Over Me' and all the others." [1](X)

Robert Picardo has written a book based on and as told by his character, named The Hologram's Handbook. Picardo goes into depth about how he felt about various experiences while aboard Voyager, such as feeling "betrayed" by Kes when she extended the length of his bout with the flu, as well as genuine and helpful advice for any holograms finding it hard to fit in with 'organics'.

In Star Trek: Voyager - String Theory: Evolution, the Doctor is sent into Ocampa's distant past by a Nacene, which transfers him into the body of a recently-deceased Ocampan soldier, allowing him to experience the sensations of an organic body for the first time, although the conditions are so harsh that he cannot fully enjoy the experience. He is eventually returned to his time after meeting with Kes to oversee the birth of an Ocampan/Nacene hybrid.

In the Voyager relaunch book series, The Doctor became a famous proponent of holographic rights and eventually joined a Federation "think tank" with Seven of Nine. Following the events of the Destiny Trilogy, The Doctor became chief surgeon of the Project Full Circle fleet, returning to the Delta Quadrant on a specialized medical ship he assisted in designing. He is subsequently the first member of the original Voyager crew to greet the resurrected Admiral Kathryn Janeway when she is restored to life by Q and Kes in The Eternal Tide. Following the discovery that Seven has formed a relationship with the Full Circle fleet's new counselor, The Doctor is reprogrammed by Zimmerman to move on from his old feelings for her, Zimmerman arguing that he is just accelerating the process of recovery that The Doctor would have gone through on his own (Protectors), but a later attempt to defeat an alien life form forces The Doctor to trap the entity in a part of his program and erase his memories of Seven, leaving him unable to even recall most of the time they have spent together (Atonement).

In the "Borg Invasion 4D" attraction at Star Trek: The Experience, The Doctor is the lead physician on board Copernicus Station on the edge of the Alpha and Delta Quadrants. While testing a group of people (the audience members) whose DNA apparently resists Borg nanoprobes, the station comes under assault by the Borg themselves. After the group of hopefuls is captured and in the process of assimilation, The Doctor breaks through the hallucination that the Borg Queen is projecting and informs them that help is on the way. Minutes later, Admiral Kathryn Janeway and the USS Voyager rescue the group and bring them back to safety. The story is helped by interactive 3D projections and real live actors. In the video segments, Robert Picardo reprises his role as The Doctor, as do Kate Mulgrew and Alice Krige for Admiral Janeway and the Borg Queen, respectively.

The Doctor (voiced by Robert Picardo) is one of several Voyager cast members who reprise their roles in the Delta Rising expansion of Star Trek Online, along with Tim Russ (Tuvok), Ethan Phillips (Neelix), Garrett Wang (Harry Kim), Jeri Ryan (Seven of Nine), and later Robert Duncan McNeill (Tom Paris). Players meet The Doctor several times as they explore the Delta Quadrant thirty years after Voyager first explored the region.